The Calculation and Testing Methods of the Thermal Transmittance of Inhomogeneous Building Envelope

Two calculation methods of the equivalent thermal resistance of inhomogeneous building envelope are demonstrated from the differential connections of thermal resistances;it shows that the formula which is resulted from the parallel-series connection is more appropriate than that from the series-parallel connection for approximately calculation of the equivalent thermal resistance.The testing of the thermal transmittance of inhomogeneous building envelope with hot box is also discussed in this paper;it shows that the heat flux that flows through the inhomogeneous building envelope may be measured by the hot-box, but the equivalent thermal resistance can not be obtained from the measuring of surface temperatures,furthermore,a new test called vacuum screen hot-box method is advanced for the testing of the thermal transmittance of inhomogeneous building envelope,and the test theory of this is also represented in this paper.